遇到异常时,如何获取类型,文件和行号?


250

捕获将这样打印的异常:

Traceback (most recent call last):
  File "c:/tmp.py", line 1, in <module>
    4 / 0
ZeroDivisionError: integer division or modulo by zero

我想将其格式化为:

ZeroDivisonError, tmp.py, 1

5
使用内置的回溯模块。
内德·迪利

这也可能是有帮助的打印的代码,其中的例外发生线:见stackoverflow.com/questions/14519177/...
Apogentus

Answers:


380
import sys, os

try:
    raise NotImplementedError("No error")
except Exception as e:
    exc_type, exc_obj, exc_tb = sys.exc_info()
    fname = os.path.split(exc_tb.tb_frame.f_code.co_filename)[1]
    print(exc_type, fname, exc_tb.tb_lineno)

51
您应该小心地将sys.exc_info()打包到局部变量中,因为如果在except处理程序中遇到异常,则局部var可能会保留在循环引用中,而不是用GC处理。最佳实践是始终仅使用sys.exc_info()的切片。或使用其他模块,如回溯,如其他海报所建议的那样。
丹尼尔·普赖登09年

1
tb只是exc_tb吗?和os.path.split(blabla)[1]是os.path.basename(balbal)
sunqiang

4
@Basj:使用sys.exc_info()[0] .__ name__可以得到类型的纯名称。
Johannes Overmann 2014年

5
@DanielPryden Python文档也使用相同的拆包方法docs.python.org/2/library/traceback.html#traceback-examples
用户

3
@RobM:是的,它是线程安全的。sys.exc_info()是在以前的API中引入的,用于处理线程安全性问题。它的输出特定于当前线程和当前堆栈帧。
user2357112支持莫妮卡

123

对我有用的最简单的形式。

import traceback

try:
    print(4/0)
except ZeroDivisionError:
    print(traceback.format_exc())

输出量

Traceback (most recent call last):
  File "/path/to/file.py", line 51, in <module>
    print(4/0)
ZeroDivisionError: division by zero

Process finished with exit code 0

7
尽管不完全是操作者想要的格式,但这是最简单,最可靠的解决方案
cs_alumnus

5
有什么强大的呢?
jouell

1
@jouell嘿,我有时也喜欢用花哨的词:)
Rishav

干净有效。感谢您的分享:)
Himanshu Gautam

49

traceback.format_exception()的(Py v2.7.3)和被调用/相关的函数有很大帮助。令人尴尬的是,我总是忘记阅读原始资料。我只是徒劳地寻找类似的细节之后才这样做的。一个简单的问题,“如何为异常重新创建与Python相同的输出,并具有所有相同的详细信息?” 这将使任何人获得90 %%以上的所需东西。沮丧,我想到了这个例子。希望对别人有帮助。(它肯定帮助了我!;-)

import sys, traceback

traceback_template = '''Traceback (most recent call last):
  File "%(filename)s", line %(lineno)s, in %(name)s
%(type)s: %(message)s\n''' # Skipping the "actual line" item

# Also note: we don't walk all the way through the frame stack in this example
# see hg.python.org/cpython/file/8dffb76faacc/Lib/traceback.py#l280
# (Imagine if the 1/0, below, were replaced by a call to test() which did 1/0.)

try:
    1/0
except:
    # http://docs.python.org/2/library/sys.html#sys.exc_info
    exc_type, exc_value, exc_traceback = sys.exc_info() # most recent (if any) by default

    '''
    Reason this _can_ be bad: If an (unhandled) exception happens AFTER this,
    or if we do not delete the labels on (not much) older versions of Py, the
    reference we created can linger.

    traceback.format_exc/print_exc do this very thing, BUT note this creates a
    temp scope within the function.
    '''

    traceback_details = {
                         'filename': exc_traceback.tb_frame.f_code.co_filename,
                         'lineno'  : exc_traceback.tb_lineno,
                         'name'    : exc_traceback.tb_frame.f_code.co_name,
                         'type'    : exc_type.__name__,
                         'message' : exc_value.message, # or see traceback._some_str()
                        }

    del(exc_type, exc_value, exc_traceback) # So we don't leave our local labels/objects dangling
    # This still isn't "completely safe", though!
    # "Best (recommended) practice: replace all exc_type, exc_value, exc_traceback
    # with sys.exc_info()[0], sys.exc_info()[1], sys.exc_info()[2]

    print
    print traceback.format_exc()
    print
    print traceback_template % traceback_details
    print

在此查询的特定答案中:

sys.exc_info()[0].__name__, os.path.basename(sys.exc_info()[2].tb_frame.f_code.co_filename), sys.exc_info()[2].tb_lineno

1
变化'message' : exc_value.message'message' : str(exc_value)进行PY3
user2682863

34

这是显示发生异常的行号的示例。

import sys
try:
    print(5/0)
except Exception as e:
    print('Error on line {}'.format(sys.exc_info()[-1].tb_lineno), type(e).__name__, e)

print('And the rest of program continues')
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